From DoomWiki.org

Codebase ZDoom
Developer(s) Graf Zahl
Initial release 0.9.1 (2005-08-30, 16 years ago)
Latest release 4.7.1 (2021-10-21, 44 days ago)
Development status Active
Written in C++
Target Platform Windows and Linux
License GPL v3 since version 3.0.0.[1][2][3]
Previously Doom Source License, 3-point BSD, others.
Website https://zdoom.org/
Source Repository



GZDoom is a ZDoom-based port which is maintained by Christoph Oelckers (Graf Zahl). It was first released on August 30, 2005 and runs on Linux, Windows and MacOS. Its development was temporarily halted on April 14, 2010, with development resuming in 2014.


GZDoom started as a new renderer for PrBoom. This early version was never publicly released, however. In 2005, Graf Zahl ported his renderer to the ZDoom Community Build, and this marked the first official release of GZDoom. The port was from then on tied to the ZDoom codebase.

On January 19, 2008, development of the port was put on hold until another official release of ZDoom is made, due to highly extensive changes to the ZDoom renderer (which consequently require extensively changing the OpenGL rendering code for compatibility) coming more frequently than Graf Zahl could catch up. An official release of ZDoom was made on February 14, 2008, and version 1.1.0 of GZDoom was released shortly afterward incorporating the changes from that version.

On April 14 2010, Graf Zahl announced on the Doomworld forums that development of GZDoom had halted. He stated his reasons as having no time to work on it, and that he was frustrated by numerous complaints about the port's lack of compatibility with ATI video cards. Graf Zahl took down the website and all its subfolders, making GZDoom temporarily unavailable except from its mirrors. The site has since been restored.

In 2014, work on GZDoom's renderer resumed. Upon release of 2.0 on August 2, 2014, OpenGL 2.x support was dropped, as the renderer was rewritten to use OpenGL 3.x and OpenGL 4.4, albeit in compatibility mode. After some time of having dual 1.9.x and 2.1.x releases, support for OpenGL 2.0 was reinstated with GZDoom 2.2.0 in 2016, but with fewer features than before in that legacy mode.

Beginning in December 2016, following ZDoom's official halt in development[4], GZDoom's development is now detached from ZDoom and the port is the first-level upstream for other forks (namely QZDoom and Zandronum), without looking back at ZDoom.

The current primary direction of development is ZScript, with several other things developed by contributors (for example, OpenGL renderer enhancements by dpJudas). Starting with version 4.3.2, support for the WAD files from the Doom Classic Unity port was added.


Merged features from QZDoom[edit]

After the QZDoom codebase got merged with GZDoom, the latter gained several new features, courtesy of Magnus Norddahl (dpJudas) and Rachael Alexanderson (Eruanna). These include:

  • Polygonal, 3-point perspective truecolor software renderer (“Softpoly”)
  • Truecolor support for the classic 2-point renderer
  • Postprocessing framework (SSAO, bloom, blur, custom post process shaders, etc.)
  • Vulkan renderer backend
  • HDR monitor support
  • ZScript JIT bytecode compiler
  • Proper windowed mode support (i.e. you can freely resize the game window)
  • Correct ZDoom software light mode for the hardware renderer
  • High resolution correct version of the software fuzz, for both software and hardware renderers
  • Improved dynamic light math, shadowmaps and spotlights
  • Materials (Classic, normal and specular maps and PBR textures), but not environment maps

See also[edit]


  • GZDoom was originally based on PrBoom, with some added code from Doom Legacy. This version was never released.[5]

External links[edit]


  1. Oelckers, Christoph (29 April 2017). "GZDoom 3.0.0 Released." ZDoom.org. Retrieved 30 April 2017.
  2. Oelckers, Christoph (16 April 2017). "Removed FMod as the last remaining piece of code that is not GPL compatible." GitHub. Retrieved 28 April 2017.
  3. Oelckers, Christoph (17 April 2017). "Removed all Doom Source license and all default Raven copyright headers and replaced them with GPLv3. Also fixed the license in a few other files." GitHub. Retrieved 28 April 2017.
  4. https://forum.zdoom.org/viewtopic.php?f=1&t=54883
  5. Oelckers, Christoph (4 December 2015). "How do you learn how to build source ports?" Doomworld Forums. Retrieved 17 December 2015.

Source code genealogy
Based on Name Base for
ZDoom GZDoom GZ3Doom
GZDoom for OS X
Tower of Babel